微信公众号开发(五)

生成二维码

从微信文档了解到,生成二维码只要调微信的接口就可以了。

创建二维码ticket

请求说明:

http请求方式: POST
URL: https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=TOKEN
POST数据格式：json
POST数据例子：{"expire_seconds": 604800, "action_name": "QR_SCENE", "action_info": {"scene": {"scene_id": 123}}}

正确的Json返回结果:{"ticket":"gQH47joAAAAAAAAAASxodHRwOi8vd2VpeGluLnFxLmNvbS9xL2taZ2Z3TVRtNzJXV1Brb3ZhYmJJAAIEZ23sUwMEmm3sUw==","expire_seconds":60,"url":"http://weixin.qq.com/q/kZgfwMTm72WWPkovabbI"}

通过ticket换取二维码

请求说明

HTTP GET请求（请使用https协议）
https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=TICKET
提醒：TICKET记得进行UrlEncode
返回说明

ticket正确情况下，http 返回码是200，是一张图片，可以直接展示或者下载。

实际开发

1.在自定义菜单添加按钮指向userAction的createQrCode方法

@RequestMapping(value="createQrCode", method=RequestMethod.GET)
public String createQrCode(Model model){
    String url = String.format(WxConfig.CREATE_TICKET, AccessTokenInfo.accessToken.getAccess_token());
    CreateQrCodeRequest req = new CreateQrCodeRequest();
    req.setExpire_seconds(1000 * 60 * 60 *24);
    req.setAction_name("QR_SCENE");
    req.setAction_info(new Action_Info(new Scene(1, "123")));
    String result = NetUtil.httpPost(url, GsonUtils.bean2json(req));
    CreateQrCodeResponse resp = GsonUtils.json2Bean(result, CreateQrCodeResponse.class); 
    model.addAttribute("ticket", resp);
    
    try {
        url = String.format(WxConfig.GET_QRCODE, URLEncoder.encode(resp.getTicket(), "UTF-8"));
        System.out.println(url);
        model.addAttribute("url", url);
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }
    return "user/qrcode";
}

CreateQrCodeRequest

package com.feng.web.model;

public class CreateQrCodeRequest {

    private Integer expire_seconds;
    private String action_name;
    private Action_Info action_info;
    
    public Integer getExpire_seconds() {
        return expire_seconds;
    }
    public void setExpire_seconds(Integer expire_seconds) {
        this.expire_seconds = expire_seconds;
    }
    public String getAction_name() {
        return action_name;
    }
    public void setAction_name(String action_name) {
        this.action_name = action_name;
    }
    public Action_Info getAction_info() {
        return action_info;
    }
    public void setAction_info(Action_Info action_info) {
        this.action_info = action_info;
    }

    public static class Action_Info{
        private Scene scene;
        public Action_Info(Scene scene) {
            super();
            this.scene = scene;
        }
        public Scene getScene() {
            return scene;
        }
        public void setScene(Scene scene) {
            this.scene = scene;
        }
    }
    
    public static class Scene{
        private int scene_id;
        private String scene_str;
        public Scene(int scene_id, String scene_str) {
            super();
            this.scene_id = scene_id;
            this.scene_str = scene_str;
        }
        public int getScene_id() {
            return scene_id;
        }
        public void setScene_id(int scene_id) {
            this.scene_id = scene_id;
        }
        public String getScene_str() {
            return scene_str;
        }
        public void setScene_str(String scene_str) {
            this.scene_str = scene_str;
        }
    }
}

CreateQrCodeResponse

package com.feng.web.model;

public class CreateQrCodeResponse {

    private String ticket;
    private Integer expire_seconds;
    private String url;
    public String getTicket() {
        return ticket;
    }
    public void setTicket(String ticket) {
        this.ticket = ticket;
    }
    public Integer getExpire_seconds() {
        return expire_seconds;
    }
    public void setExpire_seconds(Integer expire_seconds) {
        this.expire_seconds = expire_seconds;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
    @Override
    public String toString() {
        return "CreateQrCodeResponse [ticket=" + ticket + ", expire_seconds="
                + expire_seconds + ", url=" + url + "]";
    }
    
}

请求路径:

public static final String CREATE_TICKET = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=%s";

public static final String GET_QRCODE = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=%s";

编写qrcode.jsp来显示结果

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>二维码</title>
</head>
<body>
    ticket: ${ticket.ticket} <br/>
    expire_seconds: ${ticket.expire_seconds} <br/>
    url: ${ticket.url} <br/>
    <img src="${url}" /> <br/>
</body>
</html>

微信调用结果

生成二维码成功，然后识别该二维码，发现产生了事件，并且微信会post到我服务器的servlet